1. Field of the Invention
This invention relates to improvements in a roller provided with a shock absorbing member of a rubber-like elastic material on the outer peripheral portion thereof.
2. Related Background Art
As a roller provided with a shock absorbing member of a rubber-like elastic material (rubber material or elastically deformable synthetic resin) on the outer peripheral portion thereof, there is known a roller 100 shown in FIGS. 7 and 8. This roller 100 is provided with an annular groove 102 on the outer peripheral portion of a body portion 101 forming a disc-like shape, and has an annular rubber ring 103 fitted in this groove 102.
Also, there is generally known a conveying roller 200 as shown in FIG. 9 wherein rollers 202 formed of thermoplastic elastomer are integrally provided on a shaft 201 (see Japanese Utility Model Application Laid-Open No. 1-58540).
As described above, the roller 100 shown in FIGS. 7 and 8 comprises the rubber ring 103 discrete from the body portion 101 and fitted in the annular groove 102 formed in the outer peripheral portion of the body portion 101. Therefore, this roller 100 has not been the possibility that when the bad conveyance of an article being conveyed occurs, for example, when paper jam or the like occurs during paper conveyance in a copying apparatus or the like, a force acts in a direction to draw the rubber ring 103 out of the groove 102 due to the rotational force of the roller 100 and therefore, the whole or part of the rubber ring 103 slips out of the groove 102. If so, in order to prevent such slipping-out, the groove 102 in the body portion 101 in which the rubber ring 103 is fitted is made too deep, it will be anticipated that the protrusion dimension of the rubber ring 103 from within the groove 102 becomes small and the shock absorbing function of this rubber ring 103 is reduced.
Also, in some cases, there has been the possibility that the rubber ring 103 slips in the groove 102 of the body portion 101 and the rotational force of the roller 100 cannot be made to appropriately act on an article being conveyed. Also, in the manufacture of the roller 100, there has been required the trouble of fitting the rubber ring 103 into the groove 102 of the body portion 101.
On the other hand, as for the conveying roller 200 shown in FIG. 9, the rollers 202 formed of thermoplastic elastomer are integrally provided on the shaft 201 and therefore, there is no possibility of the rollers 202 slipping off the shaft 201, however, the shape keeping power of the rollers 202 is low and this has unavoidably led to the necessity of making the rollers 202 relatively thick toward the axial direction of the shaft 201 in order to give the rollers 202 a certain degree of rigidity so that when an article or the like being conveyed is urged against the rollers 202, no hindrance may be caused in the conveyance of the article by the deformation of the rollers 202.